The present invention relates to scissor jack work surface lifts and more specifically to an adjustable height desk, workbench, and the like.
Work surface scissor jack lifts are generally well known and understood with an even number of links or stacked pairs of scissor links as are shown in drawing FIGS. 1 and 2. These known scissor jack lift configurations have a link 50 pivotally connected 52 with a foundation 70 and supporting a table 72 in sliding engagement 54. Further, another link 60 is pivotally connected 62 with the table 72 and is supported by the foundation 70 in sliding engagement 64. The two links may commonly be pivotally interconnected with an interconnecting pivot 86 that is located at a common midpoint of the respective links.
A stance 80 may be defined by the pivot 52 and the extent of the stroke of the sliding engagement 64. A bearing length 82 is likewise defined by the pivot 62 and the extent of the stroke of the sliding engagement 54. The length of the stance 80 and the bearing length 82 are commonly substantially the same as a matter of geometry.
Alternatively, the interconnecting pivot 86 between the links 50 and 60 may be offset (not shown). As shown the pivot is centered. When the pivot is offset toward the foundation 70, the bearing length 82 becomes greater than the stance 80. Conversely, when the pivot is offset toward the table 72, the stance becomes greater than the bearing length.
None of these geometries is desirable in a height adjustable desk, workbench, or table work surface 72 and the like. In the situation of a centered pivot 86, the foundation 70 extends flush with the table such that an underlying floor is not clear. Rather, the floor is obstructed by the foundation such that the foundation may trip or otherwise interfere with a user.
When the pivot 86 is offset toward the foundation 70, the table 72 may be located in a lowered position adjacent a wall and the like, yet will move away from the wall when elevated. Thus, the surface encroaches on user space. Also, the range of elevation is diminished as compared with the centered pivot situation. Further, the stance 80 is less than the bearing length 82 such that an unacceptably reduced table stability may result.
Conversely, offsetting the pivot 86 toward the table 72 precludes preferred placement of the table adjacent a wall or other object because the stance 80 exceeds the bearing length 82. Thus, the foundation 70 also extends beyond, not merely flush with, the table and exacerbates the floor obstruction noted above.
Further, known work surface scissor jack lifts typically presume mounting or support from a horizontal surface, including a floor or the like. This inherently limits utility of such lifts in combination with vertical surfaces, including cabinets, walls, and panels and the like.
Thus, a need for an odd link work surface lift of the present invention is readily understood.